Overhead door actuator



May 5, 1953 B. RITTER OVERHEAD DOOR ACTUATOR 2 SHEETS-SHEET 1 Filed NOV.10. 1947 INVENTOR.

BERT'RITTER LKT O RNEYS B. RITTER OVERHEAD DOOR ACTUATOR May 5, 1953 2SHEETSSHEET 2 Filed NOV. 10, 1947 I -INVENTOR.

BERT RITTER ATTORNEYS Patented May 5, 1953 OVERHEAD DOQR ACTUATOR BertRitter, Detroit, Mich., assignor, by mesne assignments, to McKee DoorCompany, Aurora, 111., a corporation of Illinois Application November10, 1947, Serial No. 785,071

7 Claims. l

The present invention relates to an overhead garage door operator and isillustrated in conjunction with an articulated or sectional door adaptedto be moved from a lower vertical position to an upper horizontalposition adjacent the ceiling of the garage by movement along tracksprovided adjacent the edges of the door. However, the invention is notlimited to use with a door of this type and in certain aspects may findapplication as operating means for quite different devices.

It is an object of the present invention to provide an overhead dooroperator characterized by the simplicity of the construction, theelimination of parts as compared with prior structures, the economy ofmanufacture and the efliciency of operation.

More particularly, it is an object of the present invention to providean overhead door operator including an improved and simplified feedscrew.

It is a further object of the present invention to provide an overheaddoor operator characterized by the flexibility of its mounting wherebythe operator may be attached to structural members of the garage whichmay be out of true and will nevertheless operate e'fficiently when somounted.

It is a further object of the present invention to provide an overheaddoor operator comprising a traveling nut mounted on a feed screw, thenot being firmly connected to a portion of the door by means which servethe additional function of preventing rotation of the nut duringrotation of the feed screw.

It is a further object of the present invention 'to provide an improvedoverhead door operator including safety means preventing injury topersons standing in the way of movement of the door.

It is a further object of the present invention to provide an improvednut and feed screw combination which may be constructed by a simplemethod completely avoiding prior expensive machining operations.

More specifically, it is a feature of the present invention to providean improved feed screw comprising a wire or similar element wound inhelical disposition about an elongated rod or tube and secured theretoonly adjacent the ends thereof.

It is a further feature of the present invention to provide forcooperation with the feed screw described above, a traveling nutcomprising a casing having mounted therein one or more pairs 01'bearings adapted to engage opposite sides of the thread on the feedscrew.

It is a further feature of the present invention to provide a clutchcomprising adjustable friction means for effecting one-way drivingconnection in combination with additional means for effecting positivedrive in the other direction.

Other objects and features of the invention will become apparent as thedescription pro ceeds, especially when taken in conjunction with theaccompanying drawings, wherein:

Figure 1 is a fragmentary perspective view of a portion of a garageshowing an overhead door provided with the improved operating means ofthe present invention;

Figure 2 is a transverse section taken from the side or the door showingthe'operating mechanism in detail;

Figure 3 is a plan view of the operating mechanism illustrated in Fig.1;

Figure 4 is a side view of the motor drive for the improved operatingmechanism;

Figure 5 is an enlarged fragmentary section on the line 5--5 of Figure3;

Figure 5A is a fragmentary longitudinal section through one end of thefeed screw 20;

Figure 6 is a horizontal section through the traveling nut illustratingits cooperation with the improved feed screw;

Figure 7 is a view of one-half of the nut structure designed to show itsbearing on the shaft of the feed screw;

Figure 8 is a side elevation, partly in section, of a driving clutch;and

Figure 9 is a section on the line 9-4! of Figure 8.

Referring now to Figure 1, there is illustrated generally at ll) agarage having a door opening II in which is mounted a sectional garagedoor indicated generally at 2 comprising individual sections, theuppermost section is of which is connected to the operating mechanismdescribed herein. Located within the garage and adjacent the edges ofthe door [2 are tracks it along which the door moves, rollers it beingmounted along the edges of the door for the purpose of guiding the dooralong the trackways.

This type of garage door is Well known and as furnished to the trade mayinclude suitable counterbalancing mechanism to reduce the effortnecessary to raise and lower the door manually. Where suchcounterbalancing mechanism is provided it may be retained so as toreduce the load on the automatic operating mechanism forming the subjectmatter of the present invention.

Briefly described in conjunction with Figure 1,

the operating mechanism comprises a feed screw having a traveling nut 2|mounted thereon, the nut being connected to the upper section |3 of thedoor through linkage indicated generally at '22. Motor means areprovided for effecting reverse rotation of the screw 20 and therebycausing the nut 2| to move forwardly or rearwardly thereon, thuslowering or raising the garage door. Suitable automatically operatedcircuit-controlling means are provided for interrupting operation of themotor as the door reaches fully open or fully closed position.

Referring more specificially now to Figures 2, 3 and following, the dooractuating mechanism comprises an elongated tube, rod or shaft which isprovided with a thread 26 formed by winding a wire tightly about theshaft 25 from adjacent one end thereof to the other and securing thewire adjacent its ends to the shaft as by welding or brazing. It isfound that the thread 26 thus formed hugs the shaft 25 tightly and thatthere is no longitudinal slip of the thread along the shaft as loads areapplied thereto. It is therefore possible to produce long threadedelements having a thread of long lead in a very economical and efficientmanner. The wire 25 may if desired be of circular cross section or ifpreferred it may be of a generally quadrilateral cross section. It isfound that in winding the wire 26 about the shaft 25, some deformationof a wire of square cross section occurs so that if it is desired toprovide a wire thread whose cross section in the completed article iss'ruare, it is necessary to employ a slightly rhomboidal wire whoseproportions are selected such that upon winding upon a particular shaftthe deformation or change in the shape of cross section of the wireresults in the provision of a wire or thread of square cross section onthe completed article. The traveling nut 2| which cooperates with thefeed screw 20 is provided at its opposite sides with projecting ears 30to which is pivoted a yoke 3| terminating in a sleeve portion 32.Interconnecting the sleeve portion 32 and the top section l3 of the dooris a link 33 which is pivoted to a bracket 34 located adjacent the upperend of the door. As best seen in Figur 2, the connection between the nut2| and the upper section l3 of the door is such that upon initiation ofmovement of the door from closed to open position, a substantial upwardcomponent of force acting on the door is provided, whereas after aportion of the door is moved along the horizontal portion of the trackl4 the pull of the traveling nut 2| and associated mechanism issubstantially horizontal.

As best seen in Figure l, the bracket 34 com prises a pair of forwardlyprojecting arms 35 which firmly support the link 33. In addition, theyoke 3| includes a pair of arms pivoted at opposite sides to the nut 2|.The result of the construction just described is that the nut isretained quite firmly against rotation solely by its interconnectionwith the top of the door, thus obviating the necessity of additionalmeans for preventing rotation of the nut as the feed screw surfaceswhich are out of true.

arms 44 each of which is provided with a threaded opening 45 adjacentits upper end. The shaft 25, for reasons of economy and to conserveweight, is preferably hollow and adjacent its ends is provided with aplug welded or otherwise secured therein as indicated at 5|, the plughaving a reduced portion 52 extending outwardly beyond the end of thetube 25. Surrounding the reduced portion 52 of the plug 50 is an endbearing sleeve 53 provided with pivot recesses 54. The arms 44 of thebracket 43 are connected to the bearing sleeve 53 by means of screws 55.One of the screws 55, as indicated to the left in Figure 5, is itselftapped to receive a supporting bolt or screw 56 having a supportingportion 51 rotatably supporting a trip rod 58 whose purpose will laterbe described.

The construction just described permits mounting of the forward end ofthe screw 20 at the forward end of the garage, the flexibility providedby the pivot connections permitting attachment of the bracket 48 to asurface which may be substantially out of line.

A similar construction is provided for supporting the rear end of thescrew 28 in that it also provides for flexibility to permit mounting onThis construction comprises an angle piece 60 best seen in Figure 4which is attached by screws or otherwise to the underside of a portionof the garage, such for example as a rafter 6|. Secured to the verticalleg of the angle piece 60, as best seen in Figure 4, is a supportingplate 62 on which is mounted a drive motor 63, a reversing and controlswitch 64 and if desired suitable remote control receiving means 65 bymeans of which the door may be opened and closed by means of a radiosignal, supersonic signal or the like.

Extending forwardly from the plate 62 is a supporting bracket 66terminating in a sleeve 61, the bracket 68 and sleeve 61 being acounterpart of the bracket 40 and sleeve 4| employed for supporting theopposite end of the screw 20. A bifurcated yoke 10 which is in allrespects similar to the bracket 43 is rotatably supported in the sleeve67 by a pin 1|. Set screws similar to the screws 55 illustrated inFigure 3 pass through threaded openings in the ends of the arms of theyoke 10 and are received in recesses of a bearing sleeve 72 similar tothe sleeve 53.

Secured to the end of the screw 20 last referred to is a drive pulley 15which may conveniently be keyed or otherwise secured to an extendingportion 76 of the plug which supports the bearing sleeve 12.

The motor 63 drives the pulley 15 through the medium of a belt 88 drivenfrom a clutch sheave 8| which is illustrated in detail in Figures 8 and9. The sheave 8|, as illustrated in these figures, comprises a driver 82driven by the motor and provided with a radially extending flange 83.Beyond the flange 83 the driver 82 has a portion 84 of reduced diameter,the outer end portion being threaded as indicated at 85. Sleeved uponthe reduced portion 84 is a friction ring 86, an annular sheave portion81 provided with two radially extending flanged bearing portions 88 and89 and a second friction ring 90. The internal diameter of the sheave8'! is substantially larger than the reduced portion 84 of the driver toreceive a one-way drive element later to be described. Also sleeved uponthe reduced po tion 84 outwardly from the second friction ring 98 is aresilient element 9| which is herein illustrated as formed ofcompressible rubber. B

yond the resilient element 91 is a nut 92 threaded to the threadedportion 85 of the driver. As will be readily apparent from an inspectionof Figure. 8, rotation of the nut 92' varies the compression of theresilient element 9| and accordingly varies the pressure betweenfriction rings 86 and 90 and the sheave element 81. Accordingly, by themechanism thus far described means are provided for effecting a frictiondrive of the sheave 81 which permits slippage between the sheave 87 anddriver 82 when a predetermined resistance to rotation is encountered.

In addition to the mechanism thus far described, there is positioned inthe annular space between the internal diameter of the. sheave 81 andthereduced portion 84 of the driver, a spirally wound flat spring 95- whichis illustrated in Figure 9 as having one end turned in' and receivedwithin a slot formed in the reduced portion Bl of the driver asindicated at 96, the outer end 91 of the spring being free within thespace. This spring serves to provide a. positive driving force in onedirection of rotation but will slip if rotation is reversed. Thus,v forexample, if the driver is rotated in the direction of the arrow inFigure 9 friction between the outer end 9"!v of the spring and the innersurface of the sheave 81 tends to expand the spring and provides a firminterlock between the parts. As the direction of rotation is reversedfriction between the spring and the inner surface of the sheave 8'!tends to wind up the spring so as to reduce its diameter and the sheave8'! slips substantially freely on the driver.

The purpose of the clutch justdescribed is to prevent injury to a personstanding in the way of movement of the door. Upward movement of the doorcannot injure an individual and accordingly the one-way clutch isarranged so that it has positive driving connections when turning in adirection toraise the door. This is found desirable since it is theraising movement of the door that requires the greatestforce. However,downward movementof the door could conceivably injure a person standingin the way of movement and accordingly the clutch is arranged so thatthe driving connection established by the spirally wound fiat spring isineffective to transmit torque upon rotation in a direction whichresults in closing movement of the door. In order to insure thatsufficient? force is available to close the door, the nut 92 may beadjusted so that sufficient friction is provided between the frictiondisks 86 and fill and the sheave 81 to insure movement of the door inclosing direction unless it encounters an obstacle.

Referring now to Figures 6 and 7,. there is illustrated in detail theconstruction of the traveling nut 2! which follows the thread of thedriving This nut is preferably formed in two screw it. halves 98 and 99adapted to be bolted or otherwise secured together by ears 180. Theinterior of each of the halves is hollowed out centrally as indicated atl fll to provide clearance for the thread 26 of the not 2!. However,adjacent the ends each of the castings is formed with a land or bearingportion Hi2 adapted to provide firm support of the nut 2! on the screw20. The land portions [82 are helically shaped to follow the helicalformation of the thread 26, as is apparent in Figure '7.

Rollers Hi5 are provided in pairs at the interior of the nut 2 theserollers being illustrated in Figure 6 as supported by pins Hi6 having a:press fit in openings suitably formed in the walls of the nut 21. Asillustrated in Figured, two pairs of rollers I05 are provided althoughthe specific number of pairs of rollers is immaterial. Thus, forexample, if the nut is designed for a relatively light load a singlepair will be suflicient. On the other hand, two such pairs are desirablein many cases in order to provide for a balancing of forces between thenut and screw. Finally, if a relatively heavy load is to be sustained itmay be desirable to provide several pairs of rollers.

Each of the rollers of a pair should be positioned such that it engagesone side of the thread 25 closely adjacent to the other roller of thepair. Preferably rollers of a pair are positioned so that the linejoining their axes extends perpendicular to the helix of the thread.

Each of the members 98 and 99 is provided with an internally threadedboss H0 adapted to receive a stud l l l which serves as a pivot mountingfor the arms of the yoke 3|. Furthermore, one of the studs H is tappedto receive an eye bolt H2, the eye of which slides upon the trip rod 58.

In order to effect automatic actuation of the motor' 63 the trip rod 58is provided with operati ing arms l 85 and H6 which carry resilientelements Ill and H8, respectively, which operate as cam followers. Thetraveling nut 2| is provided with a pair of cams H9 and [-20,respectively. As the nut 2i moves to the right as seen in Figure 2. thecam (2E1 engages the cam follower H8 and rotates the trip rod 58. Thetrip rod 53 at its inner end carries an actuating arm I25, best seen inFigure 4. The arm I25 is connected by a link I26 to a switch lever l2'l.Opposite travel of the nut results in reverse rotation of the trip rod58 caused by engagement between the cam H9 and the cam follower HT. Inthe event that remote control signal apparatus is employed the camoperation of the switch l2! results in stopping the motor 63 andpreparing the circuit for reverse operation upon receiving the nextsignal.

The drawings and the foregoing specification constitute a description ofthe improved overhead door actuator in such full, clear, concise andexact terms as to enable any person skilled in the art to practice theinvention, the scope of which is indicated by the appended claims.

What I claim as my invention is:

'1. Inan overhead garage door operator for moving a door between openand closed position, a threaded shaft and traveling nut mounted. on saidshaft, means for connecting said nut to said door to raise and lowersaid door when said nut moved longitudinally along said shaft, a motorfor rotating said shaft, a clutch having adjustable friction devices fortransmitting power to rotate the shaft in one direction, and a onewaydrive device fortransmitting power to rotate said shaft in the oppositedirection, said one-way drive element and clutch comprisinga drivingshaft part, a driven sleeve part received over said shaft part, a secondnut mounted on said driving shaft part, a resilient element disposedbetween said parts, said nut serving to compress said element betweensaid parts and a spirally wound ribbon spring secured at one end to oneof said parts, the other end of said spring being free.

2. In an overhead garage door operator for moving a door between aclosed and open position a threaded shaft supported above the door, atraveling nut threadably mounted on said shaft, a link pivotallyconnected to said not and to said door adjacent the upper edge thereof,

said link constituting the only connection between said nut and saiddoor, a motor for rotating said shaft, said nut being moved along saidshaft to move said door when said shaft is rotated, and drive means fortransmitting power from said motor to said shaft, said drive meansincluding a driver member rotated by said motor, a driven memberconnected to rotate the shaft, a compressible resilient element disposedto transmit rotation between said driver and driven members to rotatesaid shaft and move said door from open to closed position, saidresilient element slipping relative to said members to stop the rotationof said shaft when a predetermined force is applied to said door, and aninterlock element mounted between said driver and driven members andadapted to positively rotate said driven member when said driver memberis rotated in one direction and, hence, rotate said shaft in a directionto move said door toward the open position and adapted to permitslippage between said members when said driver member is rotated in theother direction.

3. In an overhead garage door operator a single shaft, a wire tightlywrapped around said shaft .and anchored thereto to form a helical threadthereon, a traveling nut on said shaft, said nut having a hollowed-outbody, a plurality of pairs of rollers pivotally mounted within thehollowedout body of said nut adjacent said shaft, the axes of saidrollers being disposed perpendicular to the axis of the shaft, eachroller of each pair engaging an opposite side of said wire to move saidnut along said shaft when the shaft is rotated, an arm connecting saidnut and door, said arm holding said nut against rotation with said shaftand forming the sole means for opening and closing said door, and motormeans for reversibly rotating said shaft.

. said hollowed-out body and having its axis perpendicular to the axisof the shaft, said rollers engaging opposite sides of said wire to movesaid nut along said shaft when the shaft is rotated, an arm connectingsaid nut and door, said arm holding said nut against rotation with saidshaft and forming the-sole means for opening and closing said door, andmotor means for reversibly rotating said shaft.

5. In an overhead garage door operator, a

. single threaded shaft and traveling nut, an arm connecting said nutand door, said arm holding said nut against rotation with said shaft andforming the sole means for opening and closing said door, a pair ofbrackets mounted above said door, a bifurcated yoke mounted on eachbracket and pivotally connected to said shaft, said shaft being disposedwithin said yokes, a pulley con- .nected to one end of said shaft, amotor for rotating said shaft, a belt connected between said motor andsaid pulley, and mounting means for said motor.

6. In an overhead garage door operator for moving a door between avertical closed position I and a horizontal open position, a singlethreaded shaft disposed above said door, a traveling nut 'mounted onsaid shaft, an arm connecting said nut and door, said arm holding saidnut against rotation with said shaft and forming the sole means foropening and closing said door, a first bifurcated yoke mounted adjacentone end of said shaft, a first sleeve member pivotally secured withinsaid first yoke, said one end of said shaft being rotatably supportedwithin said first sleeve,

a second bifurcated yoke mounted adjacent the other end of said shaft, asecond sleeve pivotally mounted within said second yoke, the other endof said shaft being rotatably carried within said second sleeve, apulley mounted on said other end of said shaft and adapted to rotatetherewith, a motor for driving said shaft, and a belt connected betweensaid motor and said pulley.

7. In an overhead garage door operator for moving a door between avertical closed position and a horizontal open position, a single shaftdisposed above the door, a wire tightly wrapped around said shaft andanchored thereto to form a helical thread thereon, a traveling nut onsaid shaft said traveling nut having a hollowed-out body, bearingsurfaces at each end of said nut contacting said shaft, a first rollerrotatably mounted Within said hollowed-out body, a second rollerrotatably mounted within said hollowedout body, said rollers havingtheir axes disposed perpendicular to the axis of the shaft, said rollersengaging opposite sides of said wire to move said nut along said shaftwhen the shaft is rotated, an arm connecting said nut and door, said armholding said nut against rotation with said shaft and forming the solemeans for opening and closing said door, a motor for rotating saidshaft,

and drive means transmitting power from said motor to said shaft, saiddrive means including a driver member rotated by said motor, a drivenmember connected to rotate said shaft, a compressed resilient elementdisposed to transmit rotation between said members thereby to rotatesaid shaft and move said door from open to closed position, saidresilient element slipping relative to said members to stop the rotation'of said shaft when a predetermined force is applied to said door, and alocking element connected between said members to positively rotate saiddriven member when said driver member is rotated in one direction and,hence, rotate said shaft in a direction to move said door toward theopen position and adapted to permit slippage .between said members whensaid driver is rotated in the other direction.

BERT BITTER.

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